1. Department of Urology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700‑8558, Japan
2. Department of Allergy and Respiratory Medicine, Okayama University Hospital, Okayama 700‑8558, Japan
3. Department of Urology, Shimane University Faculty of Medicine, Izumo, Shimane 693‑8501, Japan